1. Field of the Invention
This invention relates to liquid separation units mounted on marine installations. More specifically, the invention relates to mechanical containment, or restraining movement, of separating oil field fluids to minimize disruption of the separation process during pitch and roll of the separation unit.
2. Description of the Prior Art
Separation of a plurality of liquids is provided by residence capacity in which gravity forces collection of the different liquids into separate bodies. Additionally, variables such as pressure, temperature, viscosity and tubulence have various effects upon the separation process.
The residence capacity is provided by the volumes of spherical, vertical or horizontal vessels. The general preference, in oil field separation, is the horizontal vessel. These generally cylindrical, horizontally extended, vessels receive oil field production in one end, and pass its fluids into contact with baffles, partitions and other structures within the vessel. Finally, the fluids are separated, formed into separate bodies, and passed from separate outlets of the vessel, remotely located from the inlet.
There are at least two classes of horizontal separator vessels. There is the simple, single, horizontal, cylinder and the double-barreled arrangement wherein two horizontal cylinders are connected by vertical conduits.
Obviously, the double-barreled separator is an efficient production tool. The mixture of fluids are flowed into the upper cylinder. As the liquids separate from the gaseous fluids they flow down the vertical conduits into the isolation provided by the lower cylinder. If the expense of fabrication and the space for installation does not become a limitation, the double-barrel separator is preferred to the simple, single, horizontal cylinder.
Shipboard separation vessels are now required by the production segment of the oil business. Marine installations now bring in the problem of pitch and roll. The liquids accumulated in the horizontally elongated separation vessels are agitated by pitch and roll. It does not take a high order of imagination to understand that the process of separating oil and water will be disrupted as wave action causes the separating liquids to displace in their separation vessel. Level controls will be disturbed and failure of the process will be evidenced by oil flowing out the water outlet and/or water flowing out the oil outlet.
The double-barrel form of separator would give some insurance of effective control of the separating liquids on a marine installation. However, where the single-barreled, monotube, form of separator must be used because of space or economical reasons, a severe problem exists. Some form of compartmenting is required to restrain, or contain, the movement of separated water in the lower volume of the separator vessel. A unique form for baffle plates must be employed in a configuration which will provide the required compartment to keep the liquids under control so their separation can take place.